package com.dp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author KT917
 * @date 2022/11/22
 */
@Component
public class RedisIdWorker {

    /**
     * 2022/1/1/0/0/0  开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1640995200;

    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    /**
     * @param keyPrefix 业务前缀
     * @return
     */
    public long nextId(String keyPrefix) {
        // 1. 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long l = now.toEpochSecond(ZoneOffset.UTC);// 当前秒数
        long timestamp = l - BEGIN_TIMESTAMP;

        //2. 生成序列号
        // 2.1 获取当前日期 精确到天
        String data = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        // 2.2 自增长
        long increment = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + data);

        //3. 拼接并返回
        return timestamp << COUNT_BITS | increment;
    }

    public static void main(String[] args) {
        LocalDateTime of = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long l = of.toEpochSecond(ZoneOffset.UTC);
        System.out.println(l);
    }

}
